Electronic air filters have heretofore been proven to be effective in the removal of airborne particles. One highly effective type of filter cell is disclosed in the Soltis U.S. Pat. No. 4,133,653 issued Jan. 9, 1979. In the cell as disclosed in the Soltis patent, the air is passed through a pre-filter and passed an ionizing wire to collecting means which may include a pair of polyurethane webs with a high voltage grid sandwiched therebetween, a high voltage source being connected to the ionizing wire and the high voltage grid. An intensive electrostatic field is formed around the wire, bombarding particles entrained in the air and imparting a charge thereto. Then, as the charged particles enter the collection zone, they encounter the charged webs an are attracted to and precipitated thereon. Such a cell may be occasionally cleaned by soaking it in a suitable detergent.
Although highly effective, such electronic air filters have not been in very extensive use, partly because of the time and expense required for installation thereof. Also, the cost of manufacture of components, especially the high voltage supply, has been quite high.
Another problem with prior art filtering apparatus has been that they have required a substantial degree of attention on the part of the owner or operator to make sure that they are operating effectively.